1. Field of the Invention
The invention relates in general to a sensing apparatus. More particularly, this invention relates to a dual type potentiometric biosensor for creatinine detection and fabricating methods thereof, which biosensor is based on an ion-selecting electrode.
2. Description of the Prior Art
A model of a biosensor is based on an analytic method of detecting a new organic compound. The analytic method was established by using the specificity theory of an enzyme and its substrate. This specificity theory is proposed by Clark et al. in 1962 (Clark L. C., C. Lyois, “Electrode system for continuous monitoring in cardiovascular surgery”, Annals of the New York Academy of Sciences, vol. 102, pp. 29-33, 1962.).
In recent years, as an electronic technology vigorously developed, a biochemistry technology has already further applied to a design of a sensor. In clinical detection of a healing institute, creatinine is one of major indexes for detecting a kidney failure of a human body. On one hand, when the creatinine density is more than 140 micro volumes Mole density (μM) above in the blood and keeps rising, it entered time of a chronic renal failure. On the other hand, by the detection of creatinine, protein absorption and dissimilation appear. The detection of creatinine simultaneously relates to functions of a kidney and a liver function, and relates to internal-secretion function of an adrenal gland. Therefore, a function of a kidney can be evaluated, if a biosensor is developed to detect creatinine. The enzyme method is more convenient than a spectral analysis method, although the spectral analysis method can be applied to directly detect a concentration of creatinine.
One of Intechno Cunsulting investigation reports (Zhang Chen-Sui, market demand and technology-developing tendency of sensors, Industrial Economics & Knowledge Center, 2002.) shows that the world market of sensors grew from 325 hundred million US dollars in 1998, to 422 hundred million US dollars in 2003. If a biotechnology combines with a semiconductor technology after devices are formed to have small sizes, products may have advantages of small volumes small, small weights, high reliabilities, high precision, low temperature and light effects, good performance, low costs is low as well as mass production. Such products have high usability in medical detection.
Accordingly, in the industry, there is a need to develop a dual type potentiometric creatinine biosensor, which biosensor is applied with a semiconductor technology. The semiconductor-combined biosensor accurately determines the concentration a sample solution, through a simple procedure.